Sliding clasp continuous fasteners



Oct. 24, 1961 G, DOELTER 3,005,247

SLIDING CLASP CONTINUOUS F'ASTENERS Filed Aug. 18, 1958 3 Sheets-Sheet 1QB-P Oct. 24, 1961 G. DoELTl-:R 3,005,247 SLIDING CLASP CONTINUOUSFASTENERS Filed Aug. 18, 1958 3 Sheets-Sheet 2 F/g @fg g5 Oct. 24, 1961G. DOELTER SLIDING CLASP CONTINUOUS FASTENERS 3 Sheets-Sheet 3 FiledAug. 18, 1958 3,005,247 Patented Get. 24, 1961 Claims The inventionrelates to sliding clasp continuous -fasteners of the kind (hereinreferred to as the kind described) in which each part of the fastener tobe joined has a succession of elements held within a fold in a sheet ortape of fabric, plastic, rubber coated fabric or like flexible materialand arranged to intercalate and interlock with the elements of the otherpart, the faces of the flexible material of the two parts on at leastone side, and usually both sides, of the folds being held in abuttingface-to-face relation at the joint when the fastener is closed and inwhich the clasp includes a plough or stripper between the two partswhich is operable to effect separation of the parts on movement of theclasp in the opening direction along the :fastener and guide means forbringing the two parts together on movement of the clasp in the closingdirection. `Usually the interlocking elements in `fasteners of this kindare held within the `folds by outer elements which clamp the flexiblematerial around root portions of the inner, interlocking, elements andthe claspV usually embraces the outer elements of the two parts andslides along the succession thereof. The folds are usually, but notnecessarily, adjacent free edges of the exible material. Examples offasteners of this kind are disclosed in Patents Nos. 2,775,- 012 and2,791,017.

Fasteners of the above rkind have the advantage that, by reason of theabutting relation of the flexible materials they may be arranged to makea joint which is uidtight even under appreciable fluid pressure.Difficulties have however been found in rendering fluid-tight theclosing end of the joint (i.e. the end to which the clasp is moved inclosing the fastener) on account of the presence of the plough. betweenthe fastener parts and the opening between the parts caused thereby. j

The invention provides a sliding clasp continuous fastener of the kinddescribed having means for sealing the opening in the joint at theclosing end caused by the plough, comprising a cover over the openingand secured to the flexible material around the opening but leaving apassageway along the joint to permit passage of the plough, said coverincluding a sealing member for said passageway adapted to be pressedinto sealing engagement with the flexible material at each side of thejoint so as to act as a seal for the passageway when the plough is inthe closed position. j

The usual applications (eg. for pressure containers) of fasteners of thekind described require that the two pieces of flexible material areopened out to lie in substantially the same plane on opposite sides ofthe joint, the joint being in the form of a rib on one face of thefastener (herein called the outer face) which projects from the plane.On the inner face of the fastener there is formed a groove (usually ofcusp shape in section) between the two pieces of flexible material whichleads along the joint to the opening aforesaid and may form a leakagepath.

The invention further provides a sliding clasp continuous. fastener ofthe kind described in which the two pieces of flexible material areopened out as just described and which has means for sealing the openingin the joint caused by the plough and the portion of the groove leadingto the closing end of the fastener comprising at the closing end a coveron the inner face of the fastener over the opening and secured to theflexible material around the opening but leaving a passageway, includingthe aforesaid portion of the groove, along the joint to permit passageof the plough, said cover including a sealing portion or member for saidpassageway which is shaped to iit into the groove and is adapted to` bepressed into sealing engagement with the flexible material in the grooveand at each side of the joint so as to act as a seal for the passagewaywhen the plough is in the closed position.

The fluid pressure acting on one `face or the other of the fastener maybe relied upon, wholly or in part, to effect the sealing engagement ofthe sealing member as aforesaid. It is however preferred that thesealing pressure is obtained or augmented by the means about to bedescribed.

in this preferred` construction the joint is held a sho-rt distance outof the `plane of the flexible material on one side thereof and thesealing member or portion projects from the plane on the same side toengage with the groove in the joint so that a tensile load onthe exiblematerial transverse to the joint (c g. the so-called hoop stressresulting `from internal fluid pressure) tends to draw the joint andgroove towards the plane into pressure engagement with the sealingmember or portion. The cover may, for example, have a cross-sectionwhich projects from the other side of the plane of the flexible materialopposite to the sealing member or` portion and there may be a piece ofsubstantially Ainextensible material around the projecting portion ofthe cover and secured to the flexible material on each side of thejoint.

A specific construction of a fastener according to the invention willnow be described by way of example and with reference to theaccompanying drawings in which:

FIGURE l is a view of the closing end of the fastener looking on theouter `face, the sliding clasp being shown a short distance away fromthe closed position,

FIGURE 2 is a view corresponding to FIGURE-1 but showing the slidingclasp in the closed position,

FIGURE 3 is a view corresponding to FIGURE 1 but showing the inner faceof the fastener, i

FIGURE 4 is a side view of the fastener; the sliding clasp being in theclosed position, t

FIGURE 5 is a section through the fastener taken on theline 5 5 inFIGURE 2,

FIGURE 6 is a section through the fastener taken on the line `6 5 inFIGURE 1 but showing the sliding clasp as it passes over the sealingmember,

FIGURE 7 is a side View of the sliding clasp,

FIGURES 8 and 9 are opposite end views of the clasp,

FIGURE 10 is a view of `the under or inner face of the clasp, and

FIGURE 11 is a section through the clasp on the line 11-11 in FIGURE 9.

Each part of the fastener comprises a flexible tape 10, 11 of rubberimpregnated fabric, the two tapes being permanently united at theclosing end 12 of the fastener as later described. Each part alsocomprises, in known manner, a row of inner elements 14 which are held infolds of the tapes by outer elements 15, the inner elements of each rowhaving heads 14a which interlock with the heads of the other row whenthe fastener is closed.

The sliding fastener clasp 16 incorporates a plough 17 for separatingthe inner elements, and guides 1S which, in co-operation with theplough, serve to bring the inner elements into their interiittinginterlocking relation as the clasp is moved to the closing end. Top andbottom projections 19' and 20 serve to lead the fastener parts to theguides 18 and plough 17.

At the closing end the two parts of the fastener are 3 v permanentlysecured together by moulding a block 21 of rubber or plastic around thelast few elements as well as by means later described.

, When the clasp is at the closing end the plough -17, as seen in FIGURE2, maintains an opening 22 between the fastener parts. The remainder ofthe fastener has the form best seen in section in FIGURE 5, that is theexible tapes 10 and 11 are held tightly in face-to-face relation at 23and 24 and are opened out away from one another to lie in substantiallythe same plane with a cusp shaped groove 26 between them. This grooveleads into the opening 22.

Adjacent the closing end there is secured to the flexible parts 10, 11(e.g; by welding, vulcanising or adhesive) a cover pad .28 of hard butliexible rubber. The pad is backed by a sheet 29 of rubber impregnatedfabric secured to the tapes 10` and 11, and also to the pad. The pad andsheet serve further to secure the ends of the tapes together.

Secured within a rectangular socket moulded in the pad 28 there is asealing bar 30 of soft rubber of which the upper surface is formed to t.into the cusp-shaped groove 26. Whereas the side portions of the pad aresecured to the tapes 10 and 11, the bar 30 and the portions 31, 32 ofthe pad aligned therewith are not so secured, thereby to provide apassageway for the plough 17 during the opening and closing of thefastener. As seen in FIGURE 9, the underface 34 of the plough is groovedto clear the top of the bar 30'.

As seen in FIGURE 5, when the two parts of the fastener are closed thetapes 10` and 11 are brought into pressure sealing face-to-faceengagement with the top of the sealing bar 30and iiow of fluid along thegroove 26 to the opening 22. is prevented. Moreover the opening 22 iscovered by the pad 28 and sheet. The pad 23 and sheet 29 serve toback-up the bar. Fluid pressure applied to the inner face of thefastener (the underface as seen in FIGURE tends further to press the baragainst the tapes and to improve the seal to an extent proportional tothe applied uid pressure. Moreover a lateral tensile or hoop stressapplied to the fastener as a result of such fluid pressureV tends todraw the tapes down onto the bar 30 and so to increase the elfectivenessof the seal. Similarly iiuid pressure applied to the outer face of thefastener tends to press the tapes into sealing engagement with the bar30, the bar being supported by the pad 28 and sheet 29 which in turn aresupported either by hoop stress applied to the sheet 29 or by directcontact between the sheet and an underlying solid support (e.g. thecontents of a container of which the fastener forms a part).

The bar 30 and the parts of the tapes which cooperate therewith may tbecoated with grease or like viscous material to improve the seal stillfurther.

The invention is not restricted to the constructional details of theabove example. For instance the sealing bar 30 and the pad 28 may beformed integrally (eg. by moulding) and the pad 28 may `be mouldedintegrally with the sheet 29.

I claim:

1. A sliding clasp continuous fastener of the kind in which each part ofthe fastener to be joined has a succession of elements held within afold of a piece of flexible material and arranged to intercalate andinterlock with the elements of the other part to form a joint betweenthe two pieces of flexible material, the faces of the flexible materialof the two parts on at least one side of t-he folds being held inabutting face-to-face relation at the joint when the joint is closed,and in which the sliding clasp includes a plough between the two partswhich is operable to effect.

separation of the parts on movement of the clasp in the openingdirection along the fastener and guide means for bringing the two partstogether on movement of the clasp in the closing direction, the ploughmaintaining an opening between the parts around the plough when moved tothe closing end of the `fastener and said Ifastener having means forsealing the opening comprising a cover over the opening and secured tothe flexible material around the opening but leaving a passageway alongthe joint to permit passage of the plough, said cover including asealing member for said passageway which makes sealing engagement underpressure with the ilexible material at each side of the joint so as toact as a seal for the passageway when the plough is in the closedposition.

2. A sliding clasp continuous fastener of the kind in which each part ofthe yfastener to be joined has a succession of elements held within afoldof a piece of flexible y material and arranged to intercalate andinterlock with the elements of the other part to form a joint betweenthe two pieces of flexible material, the faces of the flexible materialof the two parts on at least one side of the folds being held inabutting face-to-face relation at the joint when the joint is closed,and the. arrangement being that on the other side of the folds of thetwo pieces of flexible material the two pieces may be opened out to liein substantially the same plane on opposite sides of the joint, thejoint then -being in the form of a rib on the face ofthe fastener whichprojects from the plane with a corresponding groove behind the rib whichleads along the joint, and in which the sliding clasp includes a ploughbetween the two parts which is operable to effect separationV of theparts on movement of the clasp in the opening direction along theyfastener `and guide means for bringing the two parts together onmovement of the clasp in the closing direction, the plough maintainingan opening between theV parts around the plough when moved to theclosing end 0f the fastener and said fastener having means for sealingthe opening comprising a cover over the opening and secured to theflexible material around t-he opening but leaving -a passageway alongthe joint to permit passage of the plough, said cover including asealing member for said passageway which is shaped to fit into thegroove aforesaid and makes sealing engagement under pressure with theflexible material in the groove and at each side of the joint so as toact as a seal for the passageway when the plough is in the closedposition.

3. A fastener as claimed in claim 2, in which the sealing memberprojects from the plane aforesaid on the same side thereof as the rib toengage with the groove in the joint so that a tensile load on theflexible material transverse to the joint tends to draw the rib andgroove towards the plane into pressure engagement with the sealingmember.

4. A fastener as claimed in claim 3, in which the cover has across-section which projects from the other side of the plane of theflexible material opposite the sealing member and there is a piece ofsubstantially inextensible material around the projecting portion of thecover and secured to the flexible material on each side of the joint.

References Cited in the le of this patent UNITED STATES PATENTS 1`1,746,565 Sundback Feb. 1l, 1930 2,800,699 Armstrong July 30, 1957 AFOREIGN PATENTS 216,356 Australia Oct. 10, 1957 711,973 Germany e Oct.9, 1941

